Influence of the Identification Procedures of the Material Model in Accurate Prediction of Incremental Sheet Forming Forces

Finite element simulations of sheet metal forming processes achieve high precision of the process model. Previous works [1] on the impact of the selection of the material law on the prediction accuracy of the formed results have shown that more sophisticated yield functions allow better prediction compared to von Mises or Hill 48 models. However, this choice increases the cost of calibration, as it requires extensive material testing, and in some cases, crystal plasticity modeling predictions. In this work, the selection of the material model is investigated with respect to the accuracy of the force prediction in single point incremental sheet forming (SPIF) simulations. It is shown that the calibration of the material model using shear tests instead of tensile tests can satisfy the required accuracy of SPIF force prediction. This study investigates the accuracy and computation cost of using only von Mises yield surface and an isotropic hardening model versus Hill 48 and Barlat Yld2004-18p yield criteria. AA7075-O cone parts are used to compare the force prediction results.